The invention relates to a method for thermally treating a product, for instance a food.
Roasting, baking, frying and sterilising are known thermal treatments to which products such as foods can be subjected. As a rule, such thermal treatments are aimed at improving the quality and the storage life of products. Roasting is for instance understood to mean a heat treatment of a food in which by means of Maillard-reactions the flavour and odour of the treated food are improved. It can also be possible to improve the colour of the food in this manner. Roasting foods is done both in continuous and batch systems, while heating takes place through direct contact with warm process air or indirectly via a heated wall. The development of flavour and odour through roasting is an extremely complicated chemical process. Reactions occur between the reducing sugars present and free amino acids, the so-called Maillard-reactions or non-enzymatic browning. The process is continued by Amadori conversion reactions and Strecker degradations. This series of different reactions may lead to a number of highly differing flavour profiles and aromas and the occurrence of undesired additional effects. In addition, in known thermal treatments of foods, eventual products are obtained whose quality and storage life often leave to be desired.